The invention relates to the reduction of draughts through vertical or horizontal sliding sash windows.
In such windows, the leaves slide in respective vertical planes being guided in respective side-by-side portions of the frame opening which are separated by a parting bead. Such windows present a particular problem from the point of view of draught exclusion because the necessity to slide precludes the leaves being a tight fit in the frame; they must have a degree of free movement. In addition, there is the problem of positioning any seals correctly relatively to the leaves.